We're planning to go CLE/CAK-FLL Sep 1-6 on UA. I'm thinking about nesting a jaunt to NAS on UP Sep 2-6. On the return, how many hours should I allow to connect from the NAS-FLL UP flight and the FLL-XXX-CLE UA flight? Does US Immigration and Customs take place at NAS or FLL? Any other qualms I should have about this plan?

Ironic Background: We don't even want to go to Ft Lauderdale; we want to go to Nassau. However, we have a free night at a nice hotel in FLL that is use or lose. So, we're going to stay there Saturday, then go to NAS on Sunday for four nights (taking advantage of a 4th night free offer) and return to FLL Thursday.

Note: Silver Airways is not an option because TSMRSRNE won't fly on non-jet equipment. Go figure.